Efficient method for determining a preferred antenna pattern

Abstract

Aspects of the present disclosure propose a method for determining preferred transmit and receive antenna patterns of a wireless device with respect to another wireless device. The method generally includes determining the beamforming or calibrating coefficients corresponding to the preferred transmit and receive antenna patterns of a wireless device iteratively.

The invention claimed is: 
     
       1. A first apparatus for determining a preferred transmit antenna pattern for wireless communications, comprising:
 a processing system configured to assign a plurality of combinations of coefficients to one or more transmit antennas of the first apparatus for transmission in a plurality of iterations, wherein a number of nonzero coefficients in each combination is adjusted in each iteration; 
 a transmitter configured to transmit, for each iteration, a plurality of reference signals to a second apparatus, wherein each reference signal is transmitted using one of the plurality of combinations of coefficients; and 
 a receiver configured to receive a message from the second apparatus, wherein the message comprises an indication of a preferred combination of coefficients for the one or more transmit antennas of the first apparatus, wherein the preferred combination of coefficients is determined based on a quality of at least one of a plurality of received reference signals at the second apparatus; 
 wherein the processing system is further configured to determine a selected transmit antenna pattern utilizing at least the preferred combination of coefficients. 
 
     
     
       2. The first apparatus of  claim 1 , wherein the transmitter is configured to transmit data to the second apparatus with the selected transmit antenna pattern. 
     
     
       3. The first apparatus of  claim 1 , wherein:
 the processing system is configured to adjust the plurality of combinations of coefficients by selecting one or more nonzero coefficients and setting any remaining coefficients to zero. 
 
     
     
       4. The first apparatus of  claim 3 , wherein:
 the processing system is further configured to alter the number of nonzero coefficients for at least one iteration. 
 
     
     
       5. The first apparatus of  claim 4 , wherein the processing system is configured to alter the number of nonzero coefficients by:
 adding another one or more nonzero coefficients to the combination of coefficients. 
 
     
     
       6. The first apparatus of  claim 1 , wherein one or more coefficients in the preferred combination of coefficients for the one or more transmit antennas correspond to one or more frequencies. 
     
     
       7. The first apparatus of  claim 1 , wherein the first and the second apparatuses are incorporated in a single apparatus. 
     
     
       8. The first apparatus of  claim 1 , wherein each coefficient is selected from a finite set of values comprising an alphabet. 
     
     
       9. The first apparatus of  claim 1 , wherein the processing system is configured to determine the selected transmit antenna pattern utilizing a beamforming codebook and the preferred combination of coefficients. 
     
     
       10. The first apparatus of  claim 9 , wherein the processing system is further configured to generate one or more additional transmit antenna patterns by utilizing the beamforming codebook and the selected transmit antenna pattern. 
     
     
       11. The first apparatus of  claim 1 , wherein the plurality of reference signals is used by the second apparatus to determine a preferred receive antenna pattern for receiving transmissions from the first apparatus to the second apparatus. 
     
     
       12. A method for wireless communications, comprising:
 assigning a plurality of combinations of coefficients to one or more transmit antennas of the first apparatus for transmission in a plurality of iterations, wherein a number of nonzero coefficients in each combination is adjusted in each iteration; 
 transmitting, for each iteration, a plurality of reference signals to a second apparatus, wherein each reference signal is transmitted using one of the plurality of combinations of coefficients; 
 receiving a message from the second apparatus, wherein the message comprises an indication of a preferred combination of coefficients for the one or more transmit antennas of the first apparatus, wherein the preferred combination of coefficients is determined based on a quality of at least one of a plurality of received reference signals at the second apparatus; and 
 determining a selected transmit antenna pattern utilizing at least the preferred combination of coefficients. 
 
     
     
       13. The method of  claim 12 , further comprising:
 transmitting data to the second apparatus with the selected transmit antenna pattern. 
 
     
     
       14. The method of  claim 12 , further comprising:
 adjusting the plurality of combinations of coefficients by selecting one or more nonzero coefficients and setting any remaining coefficients to zero. 
 
     
     
       15. The method of  claim 14 , further comprising:
 altering the number of nonzero coefficients for at least one iteration. 
 
     
     
       16. The method of  claim 15 , wherein the altering of the number of nonzero coefficients comprises:
 adding another one or more nonzero coefficients to the combination of coefficients. 
 
     
     
       17. The method of  claim 12 , wherein one or more coefficients in the preferred combination of coefficients for the one or more transmit antennas correspond to one or more frequencies. 
     
     
       18. The method of  claim 12 , wherein the first and the second apparatuses are incorporated in a single apparatus. 
     
     
       19. The method of  claim 12 , wherein each coefficient is selected from a finite set of values comprising an alphabet. 
     
     
       20. The method of  claim 12 , wherein the determining of the selected transmit antenna pattern comprises:
 determining the selected transmit antenna pattern utilizing a beamforming codebook and the preferred combination of coefficients. 
 
     
     
       21. The method of  claim 20 , further comprising:
 generating one or more additional transmit antenna patterns by utilizing the beamforming codebook and the selected transmit antenna pattern. 
 
     
     
       22. The method of  claim 12 ,
 wherein the plurality of reference signals is used by the second apparatus to determine a preferred receive antenna pattern for receiving transmissions from the first apparatus to the second apparatus. 
 
     
     
       23. A first apparatus for wireless communications, comprising:
 means for assigning a plurality of combinations of coefficients to one or more transmit antennas of the first apparatus for transmission in a plurality of iterations, wherein a number of nonzero coefficients in each combination is adjusted in each iteration; 
 means for transmitting, for each iteration, a plurality of reference signals to a second apparatus, wherein each reference signal is transmitted using one of the plurality of combinations of coefficients; 
 means for receiving a message from the second apparatus, wherein the message comprises an indication of a preferred combination of coefficients for the one or more transmit antennas of the first apparatus, wherein the preferred combination of coefficients is determined based on a quality of at least one of a plurality of received reference signals at the second apparatus; and 
 means for determining a selected transmit antenna pattern utilizing at least the preferred combination of coefficients. 
 
     
     
       24. The first apparatus of  claim 23 , further comprising:
 means for transmitting data to the second apparatus with the selected transmit antenna pattern. 
 
     
     
       25. The first apparatus of  claim 23 , further comprising:
 means for adjusting the plurality of combinations of coefficients by selecting one or more nonzero coefficients and setting any remaining coefficients to zero. 
 
     
     
       26. The first apparatus of  claim 23 , further comprising:
 means for altering the number of nonzero coefficients for at least one iteration. 
 
     
     
       27. The first apparatus of  claim 26 , wherein the means for altering the number of nonzero coefficients comprises:
 means for adding another one or more nonzero coefficients to the combination of coefficients. 
 
     
     
       28. The first apparatus of  claim 23 , wherein one or more coefficients in the preferred combination of coefficients for the one or more transmit antennas correspond to one or more frequencies. 
     
     
       29. The first apparatus of  claim 23 , wherein the first and the second apparatuses are incorporated in a single apparatus. 
     
     
       30. The first apparatus of  claim 23 , wherein each coefficient is selected from a finite set of values comprising an alphabet. 
     
     
       31. The first apparatus of  claim 23 , wherein the means for determining the selected transmit antenna pattern comprises:
 means for determining the selected transmit antenna pattern utilizing a beamforming codebook and the preferred combination of coefficients. 
 
     
     
       32. The first apparatus of  claim 31 , further comprising:
 means for generating one or more additional transmit antenna patterns by utilizing the beamforming codebook and the selected transmit antenna pattern. 
 
     
     
       33. The first apparatus of  claim 23 , wherein the plurality of reference signals is used by the second apparatus to determine a preferred receive antenna pattern for receiving transmissions from the first apparatus to the second apparatus. 
     
     
       34. A computer-program product for determining a preferred transmit antenna pattern, comprising a non-transitory computer-readable medium comprising instructions executable for:
 assigning a plurality of combinations of coefficients to one or more transmit antennas of a first apparatus for transmission in a plurality of iterations, wherein a number of nonzero coefficients in each combination is adjusted in each iteration; 
 transmitting, for each iteration, a plurality of reference signals to a second apparatus, wherein each reference signal is transmitted using one of the plurality of combinations of coefficients; 
 receiving a message from the second apparatus, wherein the message comprises an indication of a preferred combination of coefficients for the one or more transmit antennas of the first apparatus, wherein the preferred combination of coefficients is determined based on a quality of at least one of a plurality of received reference signals at the second apparatus; and 
 determining a selected transmit antenna pattern utilizing at least the preferred combination of coefficients. 
 
     
     
       35. A station for wireless communications, comprising:
 a plurality of antennas; 
 a processing system configured to assign a plurality of combinations of coefficients to one or more transmit antennas of the station for transmission in a plurality of iterations, wherein a number of nonzero coefficients in each combination is adjusted in each iteration; 
 a transmitter configured to transmit, for each iteration, a plurality of reference signals to an apparatus, wherein each reference signal is transmitted using one of the plurality of combinations of coefficients; and 
 a receiver configured to receive a message from the apparatus, wherein the message comprises an indication of a preferred combination of coefficients for the one or more transmit antennas of the station, wherein the preferred combination of coefficients is determined based on a quality of at least one of a plurality of received reference signals at the apparatus; 
 wherein the processing system is further configured to determine a selected transmit antenna pattern utilizing at least the preferred combination of coefficients.